Reference Selector

This reference selector allows you to select a product for your orderline.
To use a reference selector you need a many-to-one association in the domain model.

The reference selector is similar to a Report Parameter except that it allows users to choose from a list of objects with which to fill an association rather than items listed in an enumeration. The selector requires you to choose an entity with which the parent object shares a reference. It will also require you to choose which attribute from that referenced entity you wish to display in the selector.

If you only want to display information, you can also use the text box. This has the added advantage that you can follow more than one association step.

General Properties

Select Using

The reference selector allows the end user to select objects by using either a drop-down or a pop-up page. If you choose to select using a page, the drop-down functionality will be replaced with a button to the right of the widget that will open a selection pop-up.

Value

Description

Page

Select the reference using a pop-up page.

Drop-down

Select the reference using a drop-down.

The advantage of a selecting using a drop-down is that it is very efficient; no page needs to be opened. The advantage of selecting using a page is that the end user can search the objects. If there are a lot of objects (say, more than 20) to select from, selecting using a page is advisable.

Default value: Drop-down

Empty Option Caption

This property represents the caption for the empty option in the drop-down reference selector shown to the user. Setting the caption is not available if the Select Using property set to the Page option. This is a translable text. For more details, see Translatable Texts.

Filling out the caption for an empty option increases the user experience of your application. It also helps screen-reader users to operate the application easily.

Select Page

The select page property determines which page is opened when the select page button is used. This page can be used to select associated objects from the list of all possible objects. This page should contain a data grid, template grid or list view connected to the same entity as the input reference set selector.

See Opening Pages. Note that opening select pages in content is prohibited.

You can generate a new page to show by right-clicking the widget and selecting ‘Generate select page…’.

Go-To Page

The go-to page gives end users quick access to a more detailed overview of the object being selected. This property determines which page is shown to the user. The page should contain a data view with the same entity as the one that is selected by the reference selector.

Go-To Page Settings

Validation Properties

The Validation type and Validation message properties were introduced in 7.6.0. They supersede the Required and Required message properties.

Validation Type

This property indicates whether this widget value should be validated and, if so, how. The possible options are no validation, a predefined validation, or a custom validation.

The possible values of a predefined validation are the following:

Required – all data types

E-mail – string

Positive number – decimal, float, integer, long

Date in the future – dateTime

Date in the past – dateTime

Custom validations are expressions that follow the Microflow expression syntax. Both $currentObject and $value are in a scope that refers to the current object and the current member value, respectively.

When a validation is set and it fails for this widget, a message will be shown when the user selects Save.

Default value: (none)

Validation Message

This property determines the message that is shown to the user if widget validation is enabled and has failed. This is a translable text (for more information, see Translatable Texts).

For example, if an address field is required, the validation message for the text box of the address could be something like, "The address is required."

Required

This property indicates whether this widget must be filled in by the end user or not. If set to true, this widget cannot be left empty, and a message will be shown if the user selects Save.

Default value: False

Required Message

This property determines the message that is shown to the user if the widget is empty and the Required property is set to true. This is a translable text (for more inforamtion, see Translatable Texts).

For example, if an address field is required, the required message for the text box of the address could be something like, "The address is required."

Formatting Properties

Decimal mode

Introduced in Mendix 7.15. In prior versions, Decimal mode could not be set and was always Fixed.

This mode only applies to the Decimal, Float (deprecated), and Currency (deprecated) attribute types.

If set to Fixed, the decimal part always will be displayed with the number of places specified in the Decimal precision property. The value will be rounded to the nearest decimal if the length of the decimal part in the attribute value exceeds the number of decimal places.

If set to Auto, the whole decimal part of the attribute value will be displayed. No decimal part will be be displayed if the attribute value is an integer.

Default value: Fixed

Examples

Value

Fixed (2)

Fixed (4)

Auto

19.0

19.00

19.0000

19

19.99

19.99

19.9900

19.99

19.9944

19.99 (*)

19.9944

19.9944

19.9999

20.00 (*)

19.9999

19.9999

19.99999

20.00 (*)

20.0000 (*)

19.99999

* The value is rounded to the nearest decimal with the defined number of decimal places.

Decimal Precision

This only applies to the Decimal, Float (deprecated), and Currency (deprecated) attribute types. From Mendix 7.15, this is available only when the Decimal mode is set to Fixed.

The precision of a value describes the number of digits that are used to express that value. This property indicates the number of decimal places (the number of digits following the point).

Default value: 2

Group Digits

For ease of reading, numbers with many digits before the decimal separator may be divided into groups using a delimiter. This property indicates whether the user will see these groups.

Default value: False

Date Format (Only for Attributes of Type Date and Time)

The date format determines whether the reference selector displays the date, time, date and time, or a custom variation of the linked attribute. How the date and/or time are formatted depend on the localization of the user viewing the data.

Default value: Date

Selectable Objects Properties

The properties in the category ‘Selectable objects’ determine the objects out of which the end user can make a selection. There are two, mutually exclusive, ways of influencing the selectable objects:

A microflow returns the list of selectable objects.

The list of objects is determined automatically taking into account the context mechanism and the properties that influence that mechanism.

Microflow

If a microflow is selected, the microflow will be called to compute the list of objects that the reference selector will show. A microflow can only be used if the selection is made using a drop-down.

Note that the other properties in this category have no effect when using a microflow!

Microflow Settings

In the microflow settings you can specify what parameters to pass to the microflow.

XPath Constraint

With the XPath constraint you can add a manual constraint to limit the list of objects that can be selected.

The XPath constraint [InStock = true()] on a reference selector for products will ensure that only products that are in stock are selectable.

This property has no effect if a microflow is used to fill the reference selector.

Constrained By

A reference selector can be constrained by one or more paths. This is typically used to make one reference selector dependent on another. For example, in page where you can edit an order line, a product selector can be constrained by a category selector. After selecting a category, the product selector is constrained by this category and shows only products in the category.

Domain model

In the domain model the order line has associations of type reference to both category and product. In this form, these can be edited with two reference selectors. The third association, from product to category, describes the relation between those two entities. Such a ‘triangle’ shaped part of the domain model is what makes constraining possible.

Form

The page has two reference selectors, one for category and one for product. The one for product is constrained by the path through the domain model that forms the triangle.

This property has no effect if a microflow is used to fill the reference selector.

Sort Order

The sort order specifies the order in which the items in the reference selector are shown. You can sort on multiple attributes in both directions (ascending and descending). If no sort order is specified, the reference selector sorts on the displayed attribute.

Default value: No sort order

Data Source Properties

Attribute Path

The attribute path specifies which attribute of an associated entity is shown in the reference selector. The path must follow one association of type reference starting in the entity of the data view.

Order_Customer/Customer/Name will allow the end user to select a user from a list of user names.

Keep in mind that even though you connect an attribute to the reference selector you are actually selecting an object. The attribute is just there to provide a visualization of the object. In this respect, the reference selector is different from other widgets like check boxes and text boxes. In those widgets you edit the value of the attribute. In the reference selector you edit an association of type reference.

Label properties

A label can be used to described the purpose of the widget to the user. The label is shown next to the widget in the user interface. If a label is configured, the widget will be rendered in the browser wrapped in a form group. See Bootstrap documentation.

Show label

This property determines whether the label is rendered and the widget is wrapped in a form group.

Default value: No

Label caption

This property is shown only when Show label is Yes. This property determines what text is rendered within a label.

Text template

The template for the label can contain parameters that are written as a number between braces (for example, {1}). The first parameter has the number 1, the second 2, etc. Note that to use template parameters, the widget must be placed in the context of an entity (for example, inside a data view or list view).

Parameters

For each parameter in the template, you define an attribute of the context entity or a referred entity, of which the value will be inserted at the position of the parameter.

Editability Properties

Editable

The editable property indicates whether the end user will be able to change the value displayed by the widget.

Value

Description

Default

The value is editable if security allows it (i.e. if the user that is signed in has write rights to the selected attribute).

Never

The value is never editable.

Conditional

The value is editable if the specified condition holds. (see below)

Default value: Default

Read-only style

This property determines how the widget is rendered if it is read-only.

Value

Description

Based on data view

Set to Control or Text by the containing data view. (Default value for widgets inside a data view)

Not enclosed by a data view

Defaults to Text. (Default value for widgets outside a data view)

Inherited from snippet call

Set to Control or Text by the containing data view of the snippet call, or Text when the snippet call is not enclosed by a data view. (Default value for widgets outside a data view inside a snippet)

Control

Widget is displayed but disabled so the value cannot be modified.

Text

Widget is replaced by a textual representation of the value.

Condition

The widget can be made editable only if the object of the data view that contains the widget satisfies the specificied criteria.

A practical example would be a personal details form in which the user must enter his marital status. In this case, you might wish to disable an input for the marriage date until the user indicates that he or she is married.

Based on Attribute Value

When selected, this enables the widget while a particular attribute has a certain value. Only Boolean and enumeration attributes can be used for this purpose.

Based on Expression

Added in Mendix 7.1.

When selected, this enables the widget while a provided expression evaluates to true. The object of the containg data view is available inside an expression as a $currentObject variable.

Note that the expression is evaluated in the browser, and hence, we advise against using “secret” values (like access keys) in it. In particular, we disallow usages of constants. Also, client-side expressions currently do not support all the functions that are available in the microflows. Please refer to an autocomplete list to know what functions are supported in your version.

Visibility Properties

Visible

By default, whether or not an element is displayed in the browser is determined by how the page is designed and the user’s roles within the application. However, the page can be configured to hide the element unless a certain condition is met.

Context

The widget can be made visible only if the object of the data view that contains the widget satisfies the specificied criteria.

A practical example would be a web shop in which the user must submit both billing and delivery information. In this case, you might not wish to bother the user with a second set of address input fields unless they indicate that the billing address and delivery address are not the same. You can accomplish this by making the delivery address fields conditionally visible based on the Boolean attribute SameBillingAndDeliveryAddress.

Based on Attribute Value

When selected, this shows the widget while a particular attribute has a certain value. Only boolean and enumeration attributes can be used for this purpose.

Based on Expression

Added in Mendix 7.1.

When selected, this shows the widget while a provided expression evaluates to true. The object of the containing data view is available inside an expression as a $currentObject variable.

Note that the expression is evaluated in the browser, and hence, we advise against using “secret” values (like access keys) in it. In particular, we disallow usages of constants. Also, client-side expressions currently do not support all the functions that are available in the microflows. Please refer to an autocomplete list to know what functions are supported in your version.

Module Roles

The widget can be made visible to a subset of the user roles available in your application. When activated, this setting will render the widget invisible to all users that are not linked to one of the selected user roles.

Events Properties

On change

The on-change property optionally specifies an action that will be executed when leaving the widget after the value has been changed.

Action

Effect

Do nothing

Nothing happens. This is useful for setting up a page without defining the underlying functionality.

Show a page

The specified page is shown.

Call a microflow

The specified microflow is executed.

Call a nanoflow

The specified nanoflow is executed.

Open link

Triggers an action based on the link type, some of which are specific to mobile devices.

Nanoflow (Only for “Call a nanoflow”)

Link Type (Only for “Open link”)

This specifies the type of action triggered when pressing the button. These are the options:

Value

Description

Web

Navigate to a website URL.

Email

Compose an email.

Call

Start a phone call.

Text

Send a text message.

Default value: Web

Address (Only for “Open link”)

Usage of the address property depends on the chosen link type. The property is used either as a URL (Web), as an email address (Email), or as a phone number (Call/Text).

The address can be set to either a literal value or an attribute value.

Address Value (Only for “Open link”)

If a literal value is chosen for the address, you can enter the value here.

Address Attribute (Only for “Open link”)

If an attribute is chosen for the address, you can select the attribute here. An address attribute specifies the path to an attribute. The path starts at the entity of the data view in which the link button is contained.

Close Page (Only for “Save changes” and “Cancel changes”)

This flag indicates whether the current page should be closed.

Sync Automatically (Only for “Save changes”)

When an object is saved in a Mendix application running in an offline profile, this information is stored in a local database until it can be synchronized with the server (for more information on the capabilities of offline apps, see Offline First. In practice, this means that uploading a new object to the server requires two distinct actions: saving the object and syncing it.

This flag indicates whether synchronization should happen when the Save button is clicked.

Common Properties

Name

The internal name of the widget. You can use this to give sensible names to widgets. The name property also appears in the generated HTML: the widget DOM element automatically includes the class mx-name-{NAME}, which can be useful for Selenium testing.

Class

The class property allows you to specify one or more cascading style sheet (CSS) classes for the widget. The classes should be separated by a space. The classes will be applied to the widget in the browser and the widget will get the corresponding styling. The classes should be classes in the theme that is used in the project. It overrules the default styling of the widget.

Styling is applied in the following order:

1) the default styling defined by the theme the project uses
2) the `Class` property of the widget
3) the `Style` property of the widget.

You can see which widgets in a page have styling applied via the class or style property by clicking the Show styles button.

Style

The style property allows you to specify additional CSS styling. If a class is also specified, this styling is applied after the class.

For example:

background-color:lightblue; color:red;

will result in red text on a blue background.

You can see which widgets in a page have styling applied via the style or class property by clicking the Show styles button.

Tab index

The tab index influences the order in which the end user navigates through the page using the tab key. By default tab indices are zero and the tab order is determined automatically by the client system. A value of minus one (-1) means that the widget will be skipped when tabbing through the page.